Every year during the Salmon fishing season in the Pacific waters of the coast of Alaska and elsewhere, millions of dollars of Salmon are caught and processed for consumption all over the world. One Salmon product likely not well known in the U.S. but highly regarded in Japan is the premium, unopened roe sacks from the female Salmon, called in Japan simply sujiko.
This product is so highly sought that one well packed, undamaged 5 kg. container can be worth $350 or more. Setting aside the details of the processing of the sujiko itself, one of the most critical stages is the method and manner of packaging, for the visual appeal to the Japanese buyer when the container is opened is of primary importance to the value of the product.
A decade or more ago, wooden 5 and 10 kg. crates were the container of choice; now that container has been supplanted by plastic pails with sealable lids. These pails are typically more or less rectangular in shape (slightly trapezoidal, for ease of palletizing, would be more accurate), and have had developed for them by leaders in the plastic container industry very sophisticated lid sealing methodologies and mechanisms.
Because the sujiko is soaked in brine as part of the final processing, and because the natural product releases its own juices, a properly packed pail of sujiko product must be drained thoroughly before it is finally sealed for shipment. In older times, the wooden crates filled with fresh product wold simply be turned upside down on plastic to drain before lidding. The better plastic pails now use a drain hole in the bottom, which is sealed with a resilient plastic plug that is press snapped into the drain hole after the product has sufficiently drained for shipment.
Typically, for reasons of weight conservation and other reasons, the plastic containers, though sturdily and artfully made and reinforced to an extent, are of a light enough gauge that a fully loaded pail of sujiko has its longer rectangular sides somewhat bowed out, to an extent that the lid designed for the pail does not ready fit onto the full pail. The pail closing and sealing process is conventionally therefore a manual operation, as is the final step of plug insertion into the drain, requiring a worker whose hands have been soaked in Salmon brine for as much as eighteen hours at a time to manipulate the bowed sides of the pail into conformity with the lid, while applying pressure downwardly on the lid to get it closed and sealed, sometimes not without the aid of a rubber hammer. When the pail is deemed fully drained after closure, the final draining being hastened by the slight compression of the product as the lid is forced on, the plug is finger inserted into the drain opening, and hammered home.
The process is tedious, inexact, time consuming and painful to the workers hands. Not infrequently, a faulty closed pail either springs open damaging or destroying the valuable product inside, or leaks during shipment to present a most unattractive appearance and smell at the docks in Japan to the buyers waiting there for the product to arrive.
What is needed is a machine to quickly and precisely receive the full containers of sujiko, with lids hand placed and started, and then close and seal them and insert the plug all in one simple and relatively effortless operation that does not require prolonged soaking of the workers hands in the brine. Such a machine should virtually insure the safe and undamaged arrival in Japan of gleaming white pallets of pristine sujiko pails.